       len
       (if (even? n)
         (recur (/ n 2) (inc len))
-        (recur (inc (* 3 n)) (inc len))))))
+        (recur (inc (*' 3 n)) (inc len))))))
 
 (defn collatz-numbers-test-cases
   "Takes a sequence of inputs and gives IO test cases of the form

   :final-report-simplifications 5000
   :max-error 1000000
   })

   :atom-generators collatz-numbers-atom-generators
   :max-points 600
   :max-points-in-initial-program 300
   :evalpush-limit 15000
   :population-size 1000
   :max-generations 300
   :parent-selection :lexicase
